SANTIAGO, CHILE
— American travelers have long been drawn to the rugged beauty of Patagonia, at the southernmost tip of South America. Its sweeping vistas are reminiscent of Wyoming, Utah, or Montana.

These days, though, some wealthy Americans are making it a permanent address.

With the cheap price of land in both Argentina and Chile, Americans are part of the great foreign buy-up and some of the leading players in reshaping what is still home to some of the last great wilderness on earth.

One of the biggest players is Doug Tompkins, cofounder of the sportswear company, Esprit. "I fell in love with the land," says Mr. Tompkins, who has created a network of 11 wilderness parks covering almost 2 million acres across Chile and Argentina. Tompkins operates under the banner of the US-registered Conservation Land Trust.

The centerpiece of the trust is Parque Pumalin in southern Chile, which covers 738,000 acres of pristine temperate rainforest and cost Tompkins more than $30 million. After six years of delays, it will officially be declared a nature sanctuary Tuesday at a ceremony here in Chile's capital, Santiago.

This agreement will give protection to the park, ban development, and offer tax breaks. Control of the park will formally be handed over to a seven-member Chilean directorate, though Tompkins will continue living there with his wife in a personal paradise. The park already attracts 10,000 visitors a year who come to enjoy the forests, waterfalls, fjords, and hot springs. There are no entry fees.

Tompkins has visited the area regularly since the early 1960s, and in 1991 purchased his first piece of land that marked the start of the park. It quickly became his new home as he left behind corporate life in San Francisco. He lives seven months of the year in Chile and the rest of the year in Argentina, pursuing his conservation projects.

While Tompkins is helping preserve the land, several large developments have sprung up recently, bringing a much needed economic boost to the region, especially on the Argentine side of the Horn.

Billionaire investor and philanthropist George Soros, based in New York, is one of the largest private landholders in Argentina. He also owns a stake in Banco Hipotecario that is a major lender to the building industry and is valued at more than $10 billion.

Before Argentina's economic crash in December 2001, Mr. Soros was the biggest cattle owner in Argentina with 170,000 head. He owned at least 2 million acres and was the leading shareholder of the luxurious Hotel Llao Llao resort at the heart of tourism in Patagonia.

According to Clarin, Argentina's leading newspaper, Soros had invested $731 million in Argentina. At a meeting in New York in September, Argentina's President Nestor Kirchner urged Soros to continue investing in Argentina. Soros would not discuss specific investments for this report.

Sparsely populated Patagonia covers about a third of Argentina and Chile - more than 400,000 square miles.

English settlers arrived more than 100 years ago and began tending sheep on the Argentine side. Today, Italian-owned clothing company Benetton continues the tradi- tion with more than 2 million acres dedicated to wool production.

Former Argentine President Carlos Menem axed restrictions on foreign ownership in the 1990s. The sell-off has been accelerated by the economic crisis where the peso has lost two-thirds of its value since the beginning of 2002.

On the Chilean side, a free-trade agreement with the US is due to start on Jan. 1 and will make investing in Chile easier and more secure for Americans.

Much of the high-profile US investment in Patagonia has centered on the provincial city of Bariloche, which is close to the major ski resorts.

In addition to Soros's stake in the Hotel Llao Llao, other major outside investors include media heavyweight Ted Turner and Charlie Lewis, who owns the Planet Hollywood franchise for South America, as well investors from Europe and neighboring Brazil.

American companies are also leading the charge to uncover mineral wealth, particularly oil and gold. ChevronTexaco is now Argentina's second largest oil producer, relying on its Patagonian oilfield, and has another 6.1 million acres to explore in the region.

In Bariloche, there are signs of resentment as Argentines live in poverty while foreigners gain advantage because of the favorable exchange rate.

Protests have blocked the road to the airport where luxury private jets are parked. A piece in the regional newspaper, the Rio Negro, listed the major foreign investors and claimed there was a dangerous trend. "A series of acquisitions by companies and famous international people underlines the sad fact that our Patagonia is being usurped," wrote Oscar Luis Mito Costa, a local citizen.

Besides the prospect of economic gain, what attracts most foreigners to Patagonia is the raw beauty and the lack of human interference. For Tompkins, it is symbolized by Parque Pumalin that, to him, is nature at its undisturbed best.

"It is an incredible place, it is a beautiful place with a lot of pristine, intact forest," he said. "The ecosystem is pretty much entirely intact, nothing is extinct."